From: John Hodge <tpg@mutabah.net>
Date: Fri, 29 Oct 2010 07:47:48 +0000 (+0800)
Subject: Bug was in Heap_Realloc
X-Git-Tag: rel0.06~6
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=a9f5c2be879ab67080122aaabe83a7ae897126bb;p=tpg%2Facess2.git

Bug was in Heap_Realloc

- Assumed sizeof(tHeapHead) == 8
- Removed debugging info
---

diff --git a/Kernel/heap.c b/Kernel/heap.c
index aa081008..abf5f27e 100644
--- a/Kernel/heap.c
+++ b/Kernel/heap.c
@@ -7,7 +7,7 @@
 #include <heap_int.h>
 
 #define WARNINGS	1
-#define	DEBUG_TRACE	1
+#define	DEBUG_TRACE	0
 #define	VERBOSE_DUMP	0
 
 // === CONSTANTS ===
@@ -340,7 +340,7 @@ void Heap_Deallocate(void *Ptr)
  */
 void *Heap_Reallocate(const char *File, int Line, void *__ptr, size_t __size)
 {
-	tHeapHead	*head = (void*)( (Uint)__ptr-8 );
+	tHeapHead	*head = (void*)( (Uint)__ptr-sizeof(tHeapHead) );
 	tHeapHead	*nextHead;
 	tHeapFoot	*foot;
 	Uint	newSize = (__size + sizeof(tHeapFoot)+sizeof(tHeapHead)+MIN_SIZE-1)&~(MIN_SIZE-1);
@@ -478,11 +478,18 @@ int Heap_IsHeapAddr(void *Ptr)
 	return 1;
 }
 
+/**
+ */
+void Heap_Validate(void)
+{
+	Heap_Dump();
+}
+
 #if WARNINGS
 void Heap_Dump(void)
 {
 	tHeapHead	*head, *badHead;
-	tHeapFoot	*foot;
+	tHeapFoot	*foot = NULL;
 	
 	head = gHeapStart;
 	while( (Uint)head < (Uint)gHeapEnd )
@@ -530,6 +537,10 @@ void Heap_Dump(void)
 		head = foot->NextHead;
 	}
 	
+	// If the heap is valid, ok!
+	if( (tVAddr)head == (tVAddr)gHeapEnd )
+		return ;
+	
 	// Check for a bad return
 	if( (tVAddr)head >= (tVAddr)gHeapEnd )
 		return ;
@@ -593,6 +604,8 @@ void Heap_Dump(void)
 		head = foot->Head;
 		Log_Debug("Heap", "head=%p", head);
 	}
+	
+	Panic("Heap_Dump - Heap is corrupted, kernel panic!");
 }
 #endif
 
diff --git a/Kernel/include/heap.h b/Kernel/include/heap.h
index 38a3f1d0..28d33c0d 100644
--- a/Kernel/include/heap.h
+++ b/Kernel/include/heap.h
@@ -12,6 +12,7 @@ extern void	*Heap_AllocateZero(const char *File, int Line, size_t Bytes);
 extern void	*Heap_Reallocate(const char *File, int Line, void *Ptr, size_t Bytes);
 extern void	Heap_Deallocate(void *Ptr);
 extern int	Heap_IsHeapAddr(void *Ptr);
+extern void	Heap_Validate(void);
 
 #define malloc(size)	Heap_Allocate(_MODULE_NAME_"/"__FILE__, __LINE__, (size))
 #define calloc(num,size)	Heap_AllocateZero(_MODULE_NAME_"/"__FILE__, __LINE__, (num)*(size))
diff --git a/Modules/Filesystems/FAT/fat.c b/Modules/Filesystems/FAT/fat.c
index 26b19613..911b26e4 100644
--- a/Modules/Filesystems/FAT/fat.c
+++ b/Modules/Filesystems/FAT/fat.c
@@ -1117,6 +1117,8 @@ char *FAT_int_GetLFN(tVFS_Node *Node, int ID)
 	tFAT_LFNCache	*cache;
 	 int	i, firstFree;
 	
+	Mutex_Acquire( &Node->Lock );
+	
 	// TODO: Thread Safety (Lock things)
 	cache = Node->Data;
 	
@@ -1126,15 +1128,20 @@ char *FAT_int_GetLFN(tVFS_Node *Node, int ID)
 		cache->NumEntries = 1;
 		cache->Entries[0].ID = ID;
 		cache->Entries[0].Data[0] = '\0';
+		Mutex_Release( &Node->Lock );
+		//Log_Debug("FAT", "Return = %p (new)", cache->Entries[0].Data);
 		return cache->Entries[0].Data;
 	}
 	
-	// Scan for a current entry
+	// Scan for this entry
 	firstFree = -1;
 	for( i = 0; i < cache->NumEntries; i++ )
 	{
-		if( cache->Entries[i].ID == ID )
+		if( cache->Entries[i].ID == ID ) {
+			Mutex_Release( &Node->Lock );
+			//Log_Debug("FAT", "Return = %p (match)", cache->Entries[i].Data);
 			return cache->Entries[i].Data;
+		}
 		if( cache->Entries[i].ID == -1 && firstFree == -1 )
 			firstFree = i;
 	}
@@ -1144,9 +1151,11 @@ char *FAT_int_GetLFN(tVFS_Node *Node, int ID)
 		i = sizeof(tFAT_LFNCache) + (cache->NumEntries+1)*sizeof(tFAT_LFNCacheEnt);
 		Node->Data = realloc( Node->Data, i );
 		if( !Node->Data ) {
-			Log_Error("FAT", "malloc() fail, unable to allocate %i for LFN cache", i);
+			Log_Error("FAT", "realloc() fail, unable to allocate %i for LFN cache", i);
+			Mutex_Release( &Node->Lock );
 			return NULL;
 		}
+		//Log_Debug("FAT", "Realloc (%i)\n", i);
 		cache = Node->Data;
 		i = cache->NumEntries;
 		cache->NumEntries ++;
@@ -1159,7 +1168,8 @@ char *FAT_int_GetLFN(tVFS_Node *Node, int ID)
 	cache->Entries[ i ].ID = ID;
 	cache->Entries[ i ].Data[0] = '\0';
 	
-	//TODO: Unlock
+	Mutex_Release( &Node->Lock );
+	//Log_Debug("FAT", "Return = %p (firstFree, i = %i)", cache->Entries[i].Data, i);
 	return cache->Entries[ i ].Data;
 }
 
@@ -1249,7 +1259,14 @@ char *FAT_ReadDir(tVFS_Node *Node, int ID)
 		lfn = FAT_int_GetLFN( Node, ID + (lfnInfo->id & 0x3F) );
 		
 		// Bit 6 indicates the start of an entry
-		if(lfnInfo->id & 0x40)	memset(lfn, 0, 256);
+		if(lfnInfo->id & 0x40) {
+			//Log_Debug("FAT", "lfn = %p", lfn);
+			//Heap_Validate();
+			//Log_Debug("FAT", "Clearing LFN");
+			memset(lfn, 0, 256);
+			//Heap_Validate();
+			//Log_Debug("FAT", "Check Passed");
+		}
 		
 		a = (lfnInfo->id & 0x3F) * 13;